Visible crew/equipment: When Johnny brings in the box and Chet removes the wrapping for the baby layette, note the unfinished set wall past Engine 51 in the apparatus bay, which we can see since the front bay door is open, but when Captain Stanley walks in telling John about the phone call, the front bay door is now closed, then when the tones drop that set wall can be seen once again.
Continuity mistake: While Roy and John are still aboard the Coast Guard helicopter during the cliff rescue at Catalina Island, when the chopper's on scene, in the overhead shot from inside the chopper, we can see where the victim is lying on the rocks, however, in the next shot from ground level, the victim is now lying on the other side of the jutting rock.
Continuity mistake: While Early, Morton, and Dixie are examining the young boy who fell, Early's wearing a gold ring (wedding band in real life) on his left hand's ring finger, but when Dixie finds the tick she asks Early to have a look, and in the closeup of the boy's head, Early's gold ring has vanished.
Continuity mistake: When Engine 8 is dispatched to "man unconscious at construction site," we see Engine 8 going past Curson Ave, then the next shot Engine 8 is driving up from the other direction of Curson Ave and passes it going the other way. Neither are flipped shots. Other than seeing the sign for Curson Ave, other giveaways are the same signs or parked vehicles.
Visible crew/equipment: When Roy tells Karen that she'll know when she can do it on her own when she'll have to, the reflection of set lighting is visible on the squad's chrome spotlight. Additionally, when Station 51 is dispatched to the structure fire the rear bay door closed, but when the rigs roll out the rear bay door is open.
Other mistake: When Station 51 is dispatched to the landslide, the engine company get into their turnouts and roll out, but in the next exterior shot as the engine drives past the camera, not only are the guys not in their turnouts, it's too obvious that none are 51's guys, and the one in Chet's jumpseat even leans forward. Presumably they're 127's guys.
Other mistake: When Station 51 is on scene at the landslide, there's a dresser on the grass in front of the house, and when the explosion occurs due to the broken gas main, in the closeups as Johnny dives to the ground there's what looks like a can of gasoline (used for the stunt perhaps) atop that dresser that wasn't there before, and it's also not in the wide shots as Johnny dives down.
Visible crew/equipment: After Roy and Johnny speak to Chet's friend the realtor, when Station 51 is being dispatched to the accident on Harbor Freeway, in the overhead shot of the apparatus bay, we can see the shadow/reflection of production equipment moving on the engine's windshield.
Other mistake: After Brackett tries unsuccessfully to get O'Brien on the line to ask about the fish tank, it cuts to an exterior shot of Station 51, and we hear the dispatcher say, "All units responding with Engine 3 cancel," but subtitles read, "Four units with Engine 3 cancelled."
Other mistake: When the man injured in the manhole is brought to treatment 6, Early tells Roy to patch him up for an EKG, but the subtitles read, "Patch one from the EKG," and then Early tells the x-ray technician to do a skull and chest series, but the subtitles read, "Skull and chest searches."
Continuity mistake: When the unconscious boy is brought to the ER, he's taken into treatment 2, with a windowless door, but when Early is doing the lumbar tap on the boy, the door behind Early has a window, and also by the way the room is set up, we know it's treatment 1 he's in, not 2.
Continuity mistake: At the restaurant, when they begin to work on getting Mrs. Merkle out from under the car, Vince sets the Biophone down on the table, and there's a netted, red glass candle on the table, but in a following closeup the candle's net has vanished and it's pinkish clear glass now. Other items on the table change as well.
Continuity mistake: When Ruthie is wheeled into the ER, Dixie tells the attendants to put her in the treatment room where Dr. Early's waiting, and they wheel her into treatment 2 which has a windowless door, but when they're in the room the door has a window, which means she's in treatment 1, not 2. Plus the fact that both treatment rooms are set up differently.
Continuity mistake: In the opening shot of Roy and Johnny at the whale tank, the maintenance guy behind them is standing between the red bleacher seats and purple seats below, but in Roy and Johnny's closeups the guy is standing between the two top purple bleacher seats, then when the whale splashes, it goes back and forth yet again.